The invention relates to a drive mechanism, and to more particularly to a drive providing in a single unit any or all of the desirable features of a bidirectional drive, an automatically self-actuated clutch with limited lost motion, and automatic self-braking. The invention is particularly useful in application to a washing machine with nutational agitation.
The invention arose during development efforts directed toward a drive mechanism having a nutational agitation cycle, as opposed to an oscillatory agitation cycle. In a washing machine having an oscillatory agitation cycle, the central fined agitator within the basket or washtub rotates back and forth in opposite directions to agitate and clean the clothes in the wash water in the basket. In a nutational washing machine, the central agitator does not oscillate back and forth in opposite rotational directions, but instead rotates in a single direction and is eccentrically oriented to define and sweep through an inverted cone shaped path during rotation, to agitate and wash the clothes in the wash water in the basket. The present invention provides a simple and efficient drive mechanism for such application.
In the present invention, the noted nutational eccentric agitator is rotated in one direction through a simple non-clutched direct drive from a driving rotary member, for example which is driven by an electric motor.
The present invention provides in combination with the noted simple direct drive, a self-actuated lost motion automatic clutch for the spin dry cycle. Upon completion of the wash and rinse cycles, it is desired to have a spin cycle to partially dry the clothes. The heavy wet clothes in the basket present a high inertia load, and it is not desirable to attempt to rotate the basket from a dead start of the driving electric motor. The present invention addresses and solves this need in a particularly simple and efficient manner, and provides the noted self-actuating lost motion clutch allowing partial starting rotation of the electric motor before engagement with the high inertia basket load. The direction of rotation of the driving rotary member for the wash cycle is opposite to the direction of rotation of such driving rotary member for the spin cycle. The drive mechanism is bidirectional, and provides direct nonclutched drive in wash direction and automatic self-actuated clutching in the spin-dry direction.
The invention also provides in combination in a single unit a self-actuated brake which automatically engages and stops rotation of the basket upon disengagement of the clutch. Conversely, engagement of the clutch substantially simultaneously disengages the brake, in response to rotation of the driving member.
The invention has other applications beyond washing machines, where the above noted and below described features are desirable.